Brain a Mashup of 'Male' and 'Female' Features

There is no such thing as a "male brain" or a "female brain," new research finds.

Instead, men and women's brains are an unpredictable mishmash of malelike and femalelike features, the study concludes. Even in brain regions previously thought to show differences based on sex, variability is more common than consistency.

"Our study demonstrates that although there are sex/gender differences in brain structure, brains do not fall into two classes, one typical of males and the other typical of females, nor are they aligned along a 'male brain–female brain' continuum," the study researchers wrote today (Nov. 30) in the journal Proceedings of the National Academy of Sciences.

"Rather, even when considering only the small group of brain features that show the largest sex/gender differences, each brain is a unique mosaic of features, some of which may be more common in females compared with males, others may be more common in males compared with females, and still others may be common in both females and males."

The new research is the first to examine sex differences in the brain as a whole. If the brain is truly sexually dimorphic, coming in a male and a female form, it should be consistently different between the two sexes, Tel Aviv University psychobiologist Daphna Joel and her colleagues wrote.

Consider the peacock, with its sexually dimorphic tail: The difference in color and size is consistent between the sexes – there's no subset of peahens brandishing iridescent purple feathers.

Clearly, brains don't fit this pattern; there is far more variation in brains within sexes than between them, a fact that has been known for a long time, said Rebecca Jordan-Young, a professor of women's gender & sexuality studies at Barnard College in New York and author of "Brain Storm: The flaws in the science of sex differences" (Harvard University Press, 2010).

Many neuroscientists had already concluded that brains are checkered with a mix of male- and femalelike structures, said Jordan-Young, who was not involved in the new study.

But despite this variation, there could still be a continuum of male-type and female-type brains, Joel and her colleagues reasoned, so long as the gender differences between structures are consistent between men and women. They decided to put the question to a test.

The researchers combed through more than 1,400 magnetic resonance images (MRI) from multiple studies of male and female brains, focusing on regions with the largest gender differences.

In the first analysis, using brain scans from 169 men and 112 women, the researchers defined "malelike" and "femalelike" as the 33 percent most extreme gender-difference scores on gray matter from 10 regions. Even with this generous designation of "male" and "female" scores, the researchers found little evidence of the consistency they would need to prove brain dimorphism.

Only 6 percent of brains were internally consistent as male or female, meaning all 10 regions were either femalelike or malelike, the researchers found. Another analysis of more than 600 brains from 18- to 26-year-olds found that only 2.4 percent were internally consistent as male or female, while substantial variability was the rule for more than half (52 percent).

In other words, there were very few individuals whose brain regions were all malelike or femalelike. And there was no clear continuum between the two endpoints.

Instead, across both gray and white matter and in connectivity patterns, brains are so overlapping that calling a particular form male or female is meaningless, Joel and her colleagues wrote.

"Our results demonstrate that even when analyses are restricted to a small number of brain regions (or connections) showing the largest sex/gender differences, internal consistency is rare and is much less common than substantial variability (i.e., being at the one end of the 'maleness-femaleness' continuum on some elements and at the other end on other elements)," they wrote.

"Anyone who is aware of current data on brain sex differences appreciates that there is no such thing as a monolithic 'male brain' or 'female brain,' in much the same way as there is no such thing as a male heart and a female heart," said Lise Eliot, a neuroscientist at Rosalind Franklin University in Chicago and author of "Pink Brain, Blue Brain: How Small Differences Grow Into Troublesome Gaps — And What We Can Do About It" (Mariner, 2010).

Eliot, who was not involved in the new study, said the research was an "innovative approach" to sifting through brain gender differences. While statistical differences between the genders exist, she told Live Science, the new study shows that the distribution of malelike and femalelike attributes is patchy, not uniform.

Indeed, previous studies have found large areas of overlap in the structure of male and female brain structures, even when population-level gender differences are found.

"Every individual could have part of both men and women in them," radiologist Ragini Verma told Live Science in 2013 after finding differences in connectivity between male and female brains.

The findings are consistent with an emerging line of research on the hormonal control of brain development, Joel and her colleagues wrote. Early on, neuroscientists had viewed sex-specific hormones as the key to sex difference in the brain, with testosterone "masculinizing" the brain and estrogen "feminizing" it.

Though hormonal influences are important, the real story is far more complex, according to a 2011 review in Nature Neuroscience.

A growing body of evidence suggests that development is a give-and-take among genetic, environmental and epigenetic (above the genome) factors, all of which are acting in parallel and influencing one another in complicated ways. Different brain regions react in different ways to sex-specific influences, which are not limited to estrogen and testosterone, that review found.

Meanwhile, environmental influences such as prenatal or early-life stress can feed back into this process, again altering how the brain develops.

Read more at Discovery News

China 'Clone Factory' Scientist Eyes Human Replication

The Chinese scientist behind the world's biggest cloning factory has technology advanced enough to replicate humans, he told AFP, and is only holding off for fear of the public reaction.

Boyalife Group and its partners are building the giant plant in the northern Chinese port of Tianjin, where it is due to go into production within the next seven months and aims for an output of one million cloned cows a year by 2020.

But cattle are only the beginning of chief executive Xu Xiaochun's ambitions.

In the factory pipeline are also thoroughbred racehorses, as well as pet and police dogs, specialised in searching and sniffing.

Boyalife is already working with its South Korean partner Sooam and the Chinese Academy of Sciences to improve primate cloning capacity to create better test animals for disease research.

And it is a short biological step from monkeys to humans -- potentially raising a host of moral and ethical controversies.

"The technology is already there," Xu said. "If this is allowed, I don't think there are other companies better than Boyalife that make better technology."

The firm does not currently engage in human cloning activities, Xu said, adding that it has to be "self-restrained" because of possible adverse reaction.

But social values can change, he pointed out, citing changing views of homosexuality and suggesting that in time humans could have more choices about their own reproduction.

"Unfortunately, currently, the only way to have a child is to have it be half its mum, half its dad," he said.

"Maybe in the future you have three choices instead of one," he went on. "You either have fifty-fifty, or you have a choice of having the genetics 100 percent from Daddy or 100 percent from Mummy. This is only a choice."

Xu, 44, went to university in Canada and the US, and has previously worked for US pharmaceutical giant Pfizer, and in drug development.

Presenting cloning as a safeguard of biodiversity, the Tianjin facility will house a gene bank capable of holding up to approximately five million cell samples frozen in liquid nitrogen -– a catalogue of the world's endangered species for future regeneration.

Boyalife's South Korean partner Sooam is already working on a project to bring the woolly mammoth back from extinction by cloning cells preserved for thousands of years in the Siberian permafrost.

Sooam also serves a niche market recreating customers' dead pet dogs, reportedly for $100,000 a time.

Sooam founder Hwang Woo-Suk was a national hero with his own postage stamp before being embroiled in controversy a decade ago after his claims to be the first in the world to clone a human embryo were discredited.

Hwang, who created Snuppy, the world's first cloned dog, in 2005, lost his university position, had two major papers retracted, and was accused of crimes ranging from violation of bioethics laws to embezzling research funds.

Earlier this year he was quoted in South Korea's Dong-A Ilbo newspaper saying that his firm was planning a cloning joint venture in China "because of South Korea's bioethics law that prohibits the use of human eggs".

"We have decided to locate the facilities in China in case we enter the phase of applying the technology to human bodies," he was quoted as saying.

For now, Xu seeks to become the world's first purveyor of "cloned" beef, breeding genetically identical super-cattle that he promises will taste like Kobe and allow butchers to "slaughter less and produce more" to meet the demands of China's booming middle class.

Cloning differs from genetic modification, but its application to animals would enable the firm to homogenise its output.

"Everything in the supermarket looks good –- it’s almost all shiny, good-looking, and uniformly shaped. For animals, we weren't able to do that in the past. But with our cloning factory, we choose to do so now," Xu said.

"Remember, this is a food. We want it to be uniform, very consistent, very premium quality," he added.

There is controversy over whether cloned beef is safe for human consumption -- research by the US Food and Drug Adminstration says that it is, but the European parliament has backed a ban on cloned animals and products in the food chain.

The UN's Food and Agriculture Organization has yet to review the issue.

Han Lanzhi, a GMO safety specialist at the Chinese Academy of Agricultural Sciences, said Boyalife’s claims about the safety, scope and timeline of their operations were alarming -- and implausible.

Read more at Discovery News

Eggshells Reveal How Dinosaurs Nested

The fragile remains of 150-million-year-old eggshells are helping researchers figure out what kinds of nests dinosaurs created for their eggs, according to a new study.

A comprehensive look at 29 types of dinosaur eggs suggests that most dinosaurs buried their eggs in nests covered with dirt and vegetation, a tactic also used by modern-day crocodiles.

But some small theropods (mostly meat-eating, bipedal dinosaurs) that were closely related to birds used another strategy: They laid their eggs in open nests, much like most birds do today, the researchers found.

"The evolution of open nests and brooding behavior could have allowed small theropod dinosaurs, and obviously birds, to move to other nesting locations other than on the ground," which may have helped their evolutionary success, said study co-researcher Darla Zelenitsky, an assistant professor of paleontology at the University of Calgary in Canada.

Researchers have spent years piecing together limited evidence about how dinosaurs raised their young, but there are few dinosaur egg fossils to study, said study lead author Kohei Tanaka, a doctoral student in the faculty of science at the University of Calgary.

"Dinosaur nest structures and nesting materials are usually not preserved in the fossil record," Tanaka said in a statement. "In the past, this lack of data has made working with dinosaur eggs and eggshells extremely difficult to determine how dinosaurs built their nests and how the eggs were incubated for hatching young."

Luckily, researchers can compare the fossilized eggs of dinosaurs to those of the dinosaur's closest living relatives: crocodiles and birds. Crocodiles bury their eggs in nests on the ground and cover them with sand, dirt and rotting vegetation, which keeps the eggs warm. In contrast, birds usually lay their eggs in open nests, and brood on them during incubation.

These modern eggs — specifically, the number and size of the pores in their shells — gave researchers clues about the nest type. They collected data on the eggs and nests of more than 120 modern species of birds and crocodiles, and found stark differences between the two.

Buried eggs tended to have a high porosity, or larger and more holes in the shell that allow for vapor and gas exchange between the outside world and the embryo. However, burying the eggs helps to retain their humidity and moisture as the embryo develops inside, Zelenitsky told Live Science.

Meanwhile, eggs in open nests (laid by brooding birds) tended to have lower porosity, "so loss of moisture is not as much an issue because gas diffusion is lower,"Zelenitsky said.

Once the researchers figured out that buried eggs tend to have high porosity, and open-nest eggs tend to have low porosity, the researchers turned their attention to the fossilized dinosaur eggs. The eggs were ancient, ranging from 150 million to 70 million years old, but they still retained crucial details, such as porosity.

Most dinosaurs, such as the long-necked sauropods, less-developed theropods and possibly the plant-eating ornithischians, had high-porosity eggs, and likely buried their eggs in nests, the researchers found. But more developed theropods, such as the maniraptorans, had eggs with low porosity, and probably laid their eggs in open nests, they said. It's unclear whether these small theropods also brooded on top of their nests, but there are fossils of small dinosaurs doing just that, which suggests that some did, Zelenitsky said.

However, these well-developed small theropods didn't lay their eggs exactly like today's modern birds. Other fossil evidence shows that early open-nesting dinosaurs still partially buried their eggs, she said.

Read more at Discovery News

Ancient Three-Armed Sea Creature a One-Of-a-Kind Find

A bizarre creature that looks like nothing alive on Earth today probably used its unique shape to collect drifting particles from the ocean to feed on, new research finds.

Tribrachidium was a denizen of the shallow seas about 550 million years ago, during the late Ediacaran period. It looked like a disc with three tentaclelike arms protruding from its flat top. Oddly, Tribrachidium had three-fold symmetry, meaning three segments were mirror images of each other. For comparison, humans have two-fold, or bilateral, symmetry, and starfish have five-fold symmetry. Nothing alive today has three-fold symmetry.

"Because we have no obvious modern comparison, that's made it really hard to work out what this organism was like when it was alive — how it moved, if it moved, how it fed, how it reproduced," said Imran Rahman, a research fellow at the University of Bristol, in the United Kingdom, who led the study.

Now, Rahman and his colleagues have used fluid dynamics to show that Tribrachidium probably was a suspension feeder, meaning it ate floating organic particles out of the water. Modern suspension feeders include brittle stars, many crustaceans and bivalves.

Tribrachidium lived about 40 million years before the Cambrian explosion, when life on Earth expanded and diversified relatively rapidly. Scientists once thought Ediacaran organisms were very simple, Rahman told Live Science, but the new findings paint a more complex picture of this time period. It's possible that Tribrachidium even altered its environment.

Suspension feeding "mobilizes organic material that was being carried around in the water column," Rahman said. "It can increase passage of sunlight through water and potentially increase oxygenation, as well."

There's no evidence that Tribrachidium could move around, so researchers thought perhaps it fed by osmotrophy, or absorbing dissolved nutrients from the water. Alternatively, it could have captured and digested larger particles by suspension feeding.

To demystify Tribrachidium's feeding habits, Rahman and his colleagues created a 3D digital model of the organism based on a cast of a fossil from south Australia. (Tribrachidium fossils have also been found in Russia and Ukraine.) They then subjected this digital model to virtual currents mimicking what would have existed in its shallow seafloor environment.

The currents slowed as they hit Tribrachidium, and then eddied in the organism's wake. These eddies served to recirculate the water back toward Tribrachidium, directing it into the nooks between its three symmetrical arms. It's very likely that gravity then settled out any waterborne particles into these crevices, allowing Tribrachidium to snag the particles and chow down.

"This is really exciting, because we didn't really have any good evidence of suspension feeding in organisms of this time period previously," Rahman said.

Other Ediacaran creatures remain mysterious, with equally weird body designs. Some, like Tribrachidium, are disc-shaped, Rahman said. Others look like fronds. He said he'd like to use similar models of fluid dynamics to figure out how those creatures might have fed.

Read more at Discovery News

Ancient Greek Temple Aligned to Full Moon

An ancient Greek temple was built to face the setting full moon near the winter solstice, according to new research that sheds new light on the orientation of sacred monuments.

A new survey of the Valley of the Temples just outside Agrigento, Italy, reveals the 2,500-year-old temples were not deliberately aligned to the rising sun, as generally believed. A variety of factors, not all of them being astronomical, inspired the ancient architects.

“Alignment was widely determined by urban layout and morphological aspects of the terrain as well as religious connections,” Giulio Magli, professor of archaeoastronomy at Milan’s Polytechnic University, told Discovery News.

Magli and colleagues Robert Hannah, at the University of Waikato, New Zealand, and Andrea Orlando, at the Catania Astrophysical Observatory, conducted the research with funding from the Ente Parco della Valle dei Templi. Their findings are published on the Cornell University physics Web site, arXiv.org.

Known as the temple of Demeter and Persephone, the shrine is among a World Heritage-listed collection of temples that once stood in full glory in Akragas, later to be called Agrigento.

“One can only imagine the spectacle at the temple. The full moon near the winter solstice – the longest night of the year – culminates very high in the sky and remains in the sky the longest,”  Magli said.

Akragas was one of the most important Greek colonies in Sicily, and the homeland of the philosopher Empedocles (490–430 BC).

Empedocles was the first to divide matter into the four elements of earth, fire, water and air. He also observed that the moon shines with light reflected from the sun.

Today the Valley of the Temples consists of the remains of 10 Doric temples dedicated to Greek gods, goddesses and heroes such as Heracles, Olympic Zeus, Demeter and Persephone, Juno, Concordia, Vulcan, Aesculapius.

Their orientation, as well that of all Greek temples, has been debated for nearly two centuries. Academics wondered whether they were aligned with astronomic events like the sunrise on specific days of the year.

Magli and colleagues measured the alignment of all the Greek temples in the valley, and showed that at least four of them are orientated in accordance with the town’s grid along the cardinal directions — irrespective of the solar date to which they would match due to the horizon.

“For such temples, only a general rule imposing the facade towards the eastern horizon was applied. However, they were not orientated toward the rising sun on specific days of the year,” Magli said.

One of the shrines, the temple of Juno, was aligned to the stars in the Delphinus constellation.

On the contrary, the temple of Zeus, one of the largest temples of the Greek world before earthquakes and Carthaginian raids, was orientated topographically in accordance with the street grid.

“Incredible as it may seem, we have been unable to find this simple explanation in the literature,” the researchers wrote.

Now incorporated in the Medieval church of San Biagio, the temple of Demeter and Persephone is preceded by a fountain sanctuary with sacred caves where votive deposits, including a statuette representing Persephone, were found.

Persephone and her mother Demeter, the goddess of nature, were the key figures in the Eleusinian mysteries representing the myth of Persephone, who was abducted by Hades to be his wife in the underworld.

The mysteries celebrated Persephone’s reunion with her mother, in a cycle with three phases, the “descent,” the “search” and the “ascent.”

“We know very little about the relationship between astronomy and those secret religious rites. A connection with the moon-orientated temple is possible and will be at the center of further research,” Magli said.

The attribution of the temple to Demeter and Persephone was also confirmed by the presence of two small circular altars located in a corridor formed between the rock cut to the north and the side of the temple.

One altar has a central well, known as bothros, which was found filled with broken kernoi, or ritual vessels of Demeter.

A relatively large esplanade can be found on the back of the temple. It was obtained artificially through the construction of huge retaining walls on the south side and an accurate excavation and leveling of the rock on the north side.

“We can imagine a nocturnal procession coming up from the fountain sanctuary and reaching the temple, in front of which, however, there is not enough space to house worshipers,” Magli and colleagues said.

Read more at Discovery News

Italian Court Acquits Six Scientists Over Quake Deaths

Earlier this month the Italian Supreme Court formally and finally overturned the convictions of six scientists who had been charged with manslaughter for failing to adequately warn of the dangers of an April 2009 earthquake that left 309 people dead.

The seismologists had participated in a meeting a week before the earthquake to discuss the dangers of recent smaller tremors in the town of L’Aquila. The original judge had found that their risk assessment of the threat of a larger earthquake had been superficial and inadequate, resulting in townspeople being wrongly reassured that they would be safe in their homes when the earthquake struck.

The complicated case began in 2010 when the six were investigated and charged, resulting in six-year prison sentences handed down in 2012; the convictions were appealed and overturned last year. That appeal was itself appealed by prosecutors who asked that the convictions be reinstated. This final ruling by the Supreme Court puts an end to the matter for all involved.

According to a Science Insider report, “Six scientists convicted of manslaughter … were definitively acquitted by Italy’s Supreme Court of Cassation in Rome following lengthy deliberations by a panel of five judges. But the court upheld the conviction of a public official tried alongside them.”

The judges found that that official, Bernardo De Bernardinis — at the time part of Italy’s civil protection department — had in fact wrongly reassured the public, while the six seismic scientists had simply stated that the chance of a major earthquake remained the same and thus had neither raised undue alarm nor downplayed the risk of the quake that soon followed. De Bernardinis’s jail time was reduced to two years.

Life is inherently risky and fraught with dangers ranging from sunlight to cigarettes to eating meat to driving in a car. Minor risks are routinely blown out of proportion in news media reports — the recent WHO finding that meat is carcinogenic is a good example –while the public regularly ignores (or tolerates) much greater risks to their health and lives when they smoke or fail to wear seat belts, for example.

The public often expects certainty from scientists about what will hurt or kill them—a certainty which science cannot provide.

From Discovery News

Earth's Magnetic Field Won't Flip Soon

This is going to come as a disturbing development, at least to those who believe that an upcoming reversal of the Earth’s magnetic field — accompanied by the North and South poles flipping in polarity — is going to signal the onset of the End Times, as prophesied in either some ancient Maya hieroglyphic text or a Black Sabbath song played backwards.

As it turns out, in an article just published in Proceedings of the National Academy of Sciences, researchers from Massachusetts Institute of Technology and Rutgers University report that the Earth is NOT heading toward an imminent doomsday magnetic shift.

The researchers report the Earth’s magnetic field has been weakening over the past 200 years, which some have interpreted as a sign of an impending temporary bottoming-out. That could result in all sorts of bad stuff happening, since the magnetic field plays an important role in shielding us from excessive solar radiation. With a too-weak field, we might see a surge in genetic mutations, It could also wreak havoc upon migratory species such as monarch butterflies, which use the magnetic field as a guide in navigation.

Fortunately, though, that’s not happening any time soon. As an MIT press release details, the researchers calculated Earth’s average, stable field intensity over the last 5 million years, and found that today’s intensity is about twice that of the historical average.

That means that the field’s intensity would have to drop a lot more before it became unstable enough to cause a reversal.

“It makes a huge difference, knowing if today’s field is a long-term average or is way above the long-term average,” says lead author Huapei Wang, a postdoctoral researcher in MIT’s Department of Earth, Atmospheric and Planetary Sciences, said in the press release. “Now we know we are way above the unstable zone. Even if the (field intensity) is dropping, we still have a long buffer that we can comfortably rely on.”

If it’s any consolation to doomsday cultists, though, Wang did note that the Earth last had a magnetic field flip 780,000 years ago, “so we are actually overdue for a flip.”

From Discovery News

'Super Corals' Could Survive Warming Oceans

If you go to a tropical paradise this winter, you'll likely snorkel on the local coral reef. If you do, take a good look, because those corals might not be around for much longer as warmer ocean temperatures kill them off.

That's why one woman, Ruth Gates, Director of the Hawai'i Institute of Biology, is working on breeding "super corals" that can withstand the climate change that oceans are already experiencing.

Another group, in Australia, is creating "mutt" corals from different robust species to achieve the same result.

What's unique about these approaches to coral preservation is that it's like the land-based genetic tinkering that's been done for millennia with livestock and crops.

"We've never taken a proactive and interventional approach" to saving corals, Gates told Discovery News at the University of Hawai'i's Coconut Island research facility on O'ahu.

Land-based agricultural breeding methods "have never been used in the oceans," she said.

But the method Gates uses is a bit different. She calls it "induced climatization" and "assisted evolution."

With this method, and drawing on 25 years of coral research, she and her team of young researchers have just begun a program working with the five dominant species of corals in Hawai'i, in the heavily polluted Kaneohe Bay. Water temperatures on the reefs there can swing from 86 to 91 degrees Fahrenheit in a day, a change that can tax even the hardiest of corals.

Why go to such lengths to save coral reefs? "Three things: food, coastal security and tourism," Gates said.

Coral reefs are home to 25 percent of marine species, according to the United Nations. 275 million people depend directly on reefs for survival and 850 million live within 62 miles of one.

Reefs protect shorelines from the effects of strong storms, breaking up wave energy that could wash away coastlines and the houses on them. As storms get stronger and more frequent with climate change, the security that reefs give coastlines will become even more important.

Coral reefs generate billions of tourism dollars worldwide; in Florida alone in 2000-2001, a four-county area in southeast Florida generated around $4.4 billion in local sales around their artificial and natural reefs.

And a report released earlier this year that compared Earth’s oceans to the world’s top 10 economies ranked them as the seventh largest, with $24 trillion in assets.

Coral Comeback

A 2014 bleaching event in Kaneohe Bay spiked water temperatures beyond what many corals could tolerate. When corals are too stressed, many will eject the tiny symbiotic algae that live on them and provide corals with many of their nutrients. The corals can die, leaving behind bleached-white skeletons.

As we snorkeled on the reef, spiky balls of ghostly-white, dead corals – some three feet or more in diameter -- stood in stark contrast to their healthy cousins. Healthy corals are a deep, rich, greenish brown color.

Back on the research boat, Gates reported seeing up to 50 percent dead corals on the parts of the reef section where we snorkeled.

But there was something else. "Corals can come back after almost totally dying," Gates said.

And, not all of the corals in the bay have been affected by bleaching or the frequent influx of pollution from the heavily populated shoreline.

Gates and her team theorized that if they could take some of these "super-performing" corals and push them to the limits of the heat, acidity and pollution they could withstand, then create offspring, the babies might end up with those same robust characteristics.

"How much stress do we have to give them before they develop a genetic memory for it?" Gates said.

"The hope is that, as parents, we can program our offspring to do better," said Raphael Ritson-Williams, a post-doctoral student on Gates' team. This is no different, he said.

The first round of the experiment formed the doctoral thesis of Hollie Putnam, an ocean scientist on Gates' team who now runs that part of the program. The offspring of super corals were raised in the lab until, in 2014, they were big enough to go back out to the reef.

The results of that experiment were published in the Journal of Experimental Biology, Gates said.

"The first babies were transplanted back to the reef with zero percent mortality and survived the bleaching" event of 2014, Gates said. "It was a very significant result."

More funding -- $4 million from Microsoft’s Paul Allen’s Vulcan Foundation -- arrived in June for the five-year program and Gates' team is about to transplant more super coral babies to one of the reefs in Kaneohe Bay.

Gates acknowledges that her work is controversial to some scientists, who think she's poo-pooing the approach of trying to mitigate climate change in favor of direct intervention.

But Steve Vollmer, Associate Director of the Marine Science Center at Northeastern University, isn’t one of them. “They are good first steps to understanding the potential for adaptation in corals,” he told Discovery News.

Read more at Discovery News

Extinction is key to terrestrial vertebrate diversity, new research reveals

Periods of high extinction on Earth, rather than evolutionary adaptations, may have been a key driver in the diversification of amniotes (today's dominant land vertebrates, including reptiles, birds, and mammals), according to new research published in Scientific Reports.

The new study reveals that mass extinctions among some groups of amniotes coincide with numerous and large diversifications in other closely related groups.

Conducted by scientists from the Museum für Naturkunde in Berlin, Germany, and the University of Lincoln, UK, the research challenges commonly held views that support a relationship between the evolution of "key innovations" in a group and the rapid increase in its number of species. The researchers behind the new study suggest the evidence for such a relationship has only ever been circumstantial.

The new study examined the issue of adaptive radiations among early amniotes, from 315 to 200 million years ago. This time period witnessed some of the most profound climate changes on a global scale, including the dramatic shrinking of the southern polar icecap, the disappearance of equatorial rainforests, a substantial increase in temperature, and prolonged drought conditions. The time period under study also included the largest mass extinction in Earth's history, about 252 million years ago.

The concept of adaptive radiation is central to modern evolutionary biology. An adaptive radiation is an extremely rapid increase in the number of species in a group, often as a result of a key evolutionary innovation, which gives the group an advantage over its competitors or allows it to exploit a new resource. Often, if the appearance of an evolutionary novelty coincides temporarily with a large increase in species richness, it is assumed that the innovation is responsible for this pattern.

The scientists used statistical methods to identify which of the amniote groups present during this time were significantly more species-rich than their close relatives, and attempted to identify the factors responsible for this diversity imbalance. The results suggest that, usually, large differences in diversity between two closely related groups are not because more species evolve in the larger group, but rather because more species of the smaller group go extinct.

A key finding of the research is that even the appearance of an important innovation in the larger group does not trigger a large proliferation of species until a major new extinction takes place.

Dr Neil Brocklehurst, a postdoc at the Museum für Naturkunde in Berlin, is the lead author of the paper. He said: "It appears that these 'key innovations' do not promote massive increases in species richness, but instead buffer against extinction when times get tough."

As part of their study, the scientists examined the evolution of the dicynodont therapsids, a group of extinct plant-eaters closely related to mammals. About 270 million years ago, dicynodonts evolved a toothless beak and a back-and-forwards motion of the lower jaw, all of which are clear functional adaptations to help them process plant material. However, it was not until 10 million years later, during a minor extinction event, that dicynodonts began to outcompete their close relatives and became hugely diverse.

A similar pattern is seen in sauropodomorph dinosaurs, the group which would go on to produce the largest land vertebrates of all times, such as the celebrated Brachiosaurus housed at the Museum für Naturkunde Berlin. The large-bodied members of this group do end up becoming significantly more diverse than their close relatives, but not until a mass extinction event that took place at the end of the Triassic, almost 30 million years after their first appearance.

Co-author Dr Marcello Ruta, Senior Lecturer in the School of Life Sciences at the University of Lincoln, UK, explained: "Using large-scale tree diagrams to depict the evolutionary relationships of various groups of organisms, it is possible to address major evolutionary questions that Charles Darwin, and many generations of biologists after him, asked. How did life become so diverse? What triggers major diversification events? How do animals and plants respond to global catastrophes?"

Read more at Science Daily

Earth Pulled a Heist on the Moon's Water

Artist’s impression of the collision that formed our moon.

While we’ve found extensive evidence of ice on the moon, it’s a very dry body compared to Earth. Some researchers say it is drier than the driest desert on our own planet. It’s an interesting dataset given that the moon was likely created after a Mars-sized body crashed into our planet several billion years ago. The shards collected into the moon, but something — some process astronomers aren’t sure about — kept most of the water on Earth.

Previous studies suggest that a bunch of water escaped from the debris of the impact before the moon was formed, but a new study has a different take. It suggests that water and other volatiles tended to deposit more on our planet because of the way the moon came together.

“We began with an existing computer simulation of the moon’s accumulation from a disk orbiting the Earth produced by a giant impact,” said Robin Canup, an astrophysicist at the Southwest Research Institute, in an e-mail interview with Discovery News. “This model was combined with models for how the temperature and chemical composition of the disk material evolve with time.”

Graphic showing all the water on Earth, compared to the size of the Earth itself.

The simulation showed that during this process, the moon picks up about half of its mass “from melt condensed in the inner portions of the disc”, Canup said, which resided between the Earth and the moon’s first orbit. As the protomoon grew larger, it continued to collide with this material, causing its orbit around the Earth to expand.

“When the Mmoon is distant enough, it can no longer efficiently accumulate inner disk melt, which is instead scattered inward and assimilated by the Earth,” Canup added. “We find that this transition occurs prior to the condensation of the depleted volatile elements, so that the final half of the Moon’s mass forms from volatile-poor melt.”

Coincidentally, Canup’s group’s work was published around the same time an article in Science suggested that volcanic rock may be responsible for at least some of the Earth’s water — as opposed to say, comets bringing water to the surface.

“We have not followed water explicitly yet in our models,” she said.  “But in order for the moon to retain water at depth, one would need to invoke a water-rich Earth and/or giant impactor before the impact, which I believe is consistent with this new paper.”

Read more at Discovery News